Antibiotics and Pets

If your pet has been prescribed antibiotics for an illness, it’s important that you that you administer the medication exactly as directed.


If your pet is ill and you are looking to buy antibiotics at a store like Tractor Supply, read this handout so that you can understand the dangers of trying to self diagnose your pet and the harm you can do by giving an antibiotic that is not suited for the kind of infection that your pet has.

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Why Does My Pet Have To Finish His Antibiotics?

If your pet was prescribed an antibiotic, it’s because we believe that he or she fighting a bacterial infection.  But in order for the medicine to work, a certain concentration of it must build up and be maintained in your pet’s body.  If the concentration is too low, only the weakest of the bacteria will die.  If the concentration is too high, your pet could get sick or suffer more severe complications.  Skipping doses or not administering all of the drug prescribed can leave some of the strongest bacterial alive, able to regrow, and able to reinfect your pet.

What Happens If I Don't Give My Pet All Of His Antibiotics?

Once antibiotic concentrations are high enough and maintained consistently in your pet’s body, the bacteria that we are trying to fight begin to die. Initially the bacteria that are most sensitive to the drug die off, but more resistant cells remain alive.  Consistent exposure to the antibiotic over time (usually 1 or 2 weeks) is sufficient to kill off even the most resistant bacteria and ensure that your pet is fully cleared of disease.  If you don’t give your pet all of his antibiotics, you risk leaving some of the harmful bacteria alive.  This colony can then regrow, but because it was spawned of more resistant parent cells, it will be harder to treat with future antibiotics and it will be more difficult to cure your pet of disease.

How Do Bacteria Become Resistant To Antibiotics?

There are two ways that bacteria become resistant to antibiotics.  The first is when bacteria are exposed to non-lethal concentrations of antibiotics.  The bacteria most resistant to the antibiotic remain alive, reproduce, and pass on their antibiotic resistance to their offspring.  The second way is through a process called conjugation.  This is when resistant microbes transfer their genetic resistance to other bacteria by exchanging small portions of genetic material in something called plasmids.  Conjugation can happen between different species of bacteria making the threat of antibiotic resistance all the more complicated and worrisome.

What is Antibiotic Resistance?

Antibiotic resistance is the immunity that bacteria achieve over time against antibiotics.  When bacteria are exposed to non-lethal doses of antibiotics, the bacteria that are most resistant to the antibiotic survive the dose and go on to reproduce more bacteria with the same resistant qualities.  These more resistant bacteria require longer exposure to the antibiotic or treatment with another antibiotic before they can be killed.  Antibiotic resistance has been called one of the most significant health threats of the 21st Century.

Why Can't I Buy Antibiotics At Tractor Supply?

The Federal Drug Administration is so concerned about the threat of antibiotic resistance that only a licensed veterinarian can prescribe antibiotics to animals.  When treating bacterial infections, it’s extremely important that the right antibiotic is selected and is dosed appropriately for duration and concentration, otherwise, the dosage risks creating antibiotic resistant bacteria.

I Have Antibiotics Left Over From My Other Pet, Can I Use Them?

No, not without the advice of a veterinarian.  Antibiotics have a shelf life.  When you give antibiotics that have surpassed their expiration date, you risk giving a non-lethal dose and making the problem worse.  Additionally, antibiotics are prescribed based on what kind of bacteria are present and where the infection is located.  For example, if you are trying to treat a skin infection with an oral antibiotic, the drug has to be digested and absorbed into the blood stream at a certain concentration.  If the antibiotic you are administering is broken down in the digestive tract before it can be absorbed, it will not work.  Conversely, applying a topical antibiotic to a skin lesion  that is caused by an internal infection of bacteria will also not be effective.  Antibiotics are prescribed based on what kind of bacteria are causing the infection and where the infection is located.

I'm Positive This Is The Same Ear Infection My Pet Had Before. Can I Just Pick Up More Antibiotics Without An Exam?

Probably not.  Here’s why.  Recurring infections are not normal. If your dog or cat is regularly troubled by skin, ear, or other infections, there is likely an underlying source to the problem.  Without determining why your pet keeps getting sick, we’ll always be stuck in a vicious cycle of treating infection in the short-term, but never fully preventing your pet from getting sick in the future.  Additionally recurring infections can be caused by resistant bacteria in which case antibiotics won’t work.  Typically recurring infections are cultured to determine the kind of bacteria that are causing the infection and to determine the best antibiotic to use to treat it.

Can I Mix My Pet's Antibiotic Into His Food?

Not really, no. It’s best to give your pet’s oral dose of antibiotic by mouth after he or she has eaten. Some antibiotics are very bitter tasting.  If you mix it into the food, your pet may not eat it or eat only part of it, and you risk missing a dose or under dosing your pet. Giving your pet a meal before an antibiotic is recommended since some antibiotics can cause stomach upset.

Some people like using a pet piller like this

to give your cat or dog a pill.  Click here to purchase on Amazon.



What's The Best Way To Pill My Dog Or Cat?

Giving your pet a pill requires patience and practice.  To give your pet a pill, stand behind him or her.  With the pill in your one hand, open your pet’s mouth with the other.  You can do this by gently squeezing the the sides of your pet’s mouth just where the upper and lower jaw meet at the head.  Gently place the pill as far back as you can in the center of your pet’s tongue. Try to get it as close to the opening of the throat as possible.  Now close your pet’s mouth and stroke the throat.  Your dog or cat will likely hold the pill in the mouth until he or she is released, so it’s important that you feel him or her swallow before you let go.  Typically a small lick of the tongue outside of the mouth is a good sign that the pet has been swallowed, but watch your pet after release to make sure the pill is not spit out.  Some people recommend gentle blowing in your pet’s face to elicit a swallow response, but some pets hate this and it may make pilling in the future more difficult.

Will Antibiotics Give My Pet Diarrhea?

It is not uncommon for pets to experience soft stools or diarrhea while being treated with antibiotics.  Talk to us about a probiotic that may help restore healthy bacteria to the gut and limit gastrointestinal upset.  It is also safe to mix a small portion of unflavored, unsweetened yogurt into your pet’s meal before giving the antibiotic as a way to coat the stomach and to restore good bacteria to the gut.

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